Check strap for looms



Feb. l0, 1948. s, D, LESESNE 2,435,749

y CHECK STRAP FOR LooMs Filed March 27, 1946 a .ab

2l-94. 3mm

l SHer'man D. Lesesn A n I wi'ness Herber E. Cove'g l Patented Feb. l0, 1948 cnscx sraAr Foa LooMs Sherman D. Lesesne, Worcester. Mass.; asslgnor to Gratonv & Knight Company. Worcester, Mass., a corporation of Massachusetts Application March 27, 1946, Serial No. 657,532

3 Claims. (Cl. 139-161) This invention relates to check straps for ily shuttle looms, and more particularly to a check strap which provides frlctional restraint to check the rearward movement of the picker stick caused by the impact of the travelling shuttle and they forward movement of the picker stick after it has thrown the shuttlefor its return motion through the loom.

A check strap is generally in the form of an endless band of leather which surrounds `the stick and is used in association with friction fingers vwhich restrain the movement of the check strap under the propelling influence of the picker stick. The check strap may also be made of a piece of leather having its ends bolted together and to the loom frame. The leather check strap is subjected to the pounding action of the rapidly moving picker stick, as well as the resisting drag of the friction fingers. But leather differs materially in its essential characteristics, as determined by differences between the hides themselves as well as the location of the chosen piece of leather in a given hide. Hence the straps have stretched to different degrees depending upon the qualities of the leather. When the strap has stretched too much, then the endless strap must be removed from the loom and thrown away while the straps of adjustable length require stopping the loom to make the necessary adjustment. It is therefore desirable that a strap have a long life of useful service without requiring stopping the loom to adjust or to replace the` check strap.

The primary object of this invention is to overcome such problems and to provide a strap which is reinforced with strengthening material that resists 'stretching of the strap and yet permits adequate flexing thereof and a satisfactory frlctional retardation of the picker stick. Other objects will be apparent in the following disclosure.

According to my invention, I make a reinforced check strap by securing strong cord strands between two layers of leather, in which the outside leather faces receive the frlctional wear of usage and the cord strands resist longitudinal stretching of the strap.

In the drawings illustrating preferred embodiments of the invention:

Fig. 1 is an isometric view of a strap reinforced by layers of fabric;

Fig. 2 is a cross section ofthe same;

Fig. 3 is a side elevation. partly in section, of an endless folded leather strap reinforced by cords;

Fig. 4 is a cross section on the line 4--4 of Fig. 5 is a section of a folded strap reinforced by fabric.

In the modification shown in Figs. land 2, the check strap is made of two separate leather strips i0 and i2, between which are secured a plurality of cord strands extending longitudinally f of the strap, such as the warp threads of one or more layers I4 of textile fabric. The strap may have holes i5 therein for bolting the strap ends together and to the loom frame. The leather is preferably oak or 'chrome tanned. The leather strips or layers I0 and I2 may be curried or filled with various traction increasing. friction resisting or leather preserving agents or otherwise suitably treated. The cord strands may be arranged in one or morelayers between the leather strips.

I prefer to use two layers of a strong fabric having its warp or strongest thread or cord running lengthwise of the check strap. The fabric may be made of woven cotton, rayon or nylon threads or cords and of sizes which have adequate tensional strength, such as is used for heavy duck or canvas. The fabric may be pretreated or of a type which will not stretch subsequently to a material extent.

rThe fabric is secured to the leather strips. and to each other, if more than one layer is used, by means of an elastic ccmentitious mastic, such as a standard rubber cement or animal glue or a plasticized cellulose nitrate cement. For instance, I may use a rubberized canvas fabric in which the rubber serves to secure the fabric to the adjacent leather strips as well as to unite multiple layers of the fabric. The rubber may be either a natural or a synthetic product. and

the fabric may be suitably embedded in the rubber or coated therewith. This may be done by coagulating rubber latex on the fabricV in the presence of sulfur and other vulcanlzing agents and fillers. A rubber solution may be used and the fabric coated therewith by evaporating the solvent. Two parallel layers of rubber coated fabric may be placed between two strips of leather, and the assembled layers are then subjected to lateral pressure to force the parts tightly together and make an intimate union between the rubber and the adjacent pore surfaces of the leather. The rubber may be compounded with required sulfur and other ingredients, as is well known in the rubber industry, to provide a satisfactory and strong vulcanized product. Also.

, a single layer of fabric. or multiple layers. may

sembly; and

be cemented in place between the leather strips by means of cellulose nitrate plasticized with camphor or other suitable plasticizing medium.

3 with the leather and provides a body which will not tear apart along the Junction line when sub- 4 is folded over, and the cement secures the parts together. The fabric reinforcement may be i made and secured in place by any of the procean endless check strap made of two layers of 4 leather between which are secured several strands of textile cord as a reinforcement material. An endless strap may be made in accordance with the procedure above described of two separate pieces of leather of required dimensions which are individually secured together in endless form one around the other, and which are cemented together with the reinforcement cord strands therebetween. A single strand of cord may be wrapped repeatedly around the inner leather layer as parallel strands, or several cords may be employed in parallel arrangement to form the strands.

The form shown in Fig. 3 is made of a single piece of leather having its ends connected together, after which one side is folded to form a double layer of U-shape in cross section. As shown in Fig. 4, the strap is formed of a single strip of leather which has more than douole the width of the check strap as indicated by the dotted outline. The strip of leather hal its ends first cemented together to form an endless band of a single layer. Then the textile cord strands 22 are wrapped longitudinally around one half of this endless band on its outer periphery. The endless leather band may be initially provided with a layer of nitrocellulose cement or of a rubber cementing mastic suitably compounded with sulphur and other materials to provide a vulcanizable medium. A single cord may be wrapped around the endless band by an ordinary spooling' operation, such as is employed for spooling thread on the bobbin of a sewing machine, and the cord ends are suitably secured in'place by the mastic or by other desired method. While the cementing medium is still plastic, the outer unwrapped half 24 of the endless leather band is folded laterally over the wrapped portion to forni the desired U-shaped structure. Suitable cement may be applied just prior to this folding operation, so that after the fold has been accomplished, the parts may be pressed together. If a plastlcized nitrocellulose cement has been used, then this is allowed to set while the two folded halves oi the endless check strap are held under pressure and at a required temperature. The single cord reinforcement has a special advantage in that there are no cross strands, orwoof, of a woven fabric ment.

The leather strap may be bent first into its final U form, and the cords thereafter suitably inserted into the space therebetween. This may be done by embedding the parallel cords in a thin sheet of vulcanizable rubber and then sliding the rubber strip, in endless form. into the folded leather.

As shown in Fig. 5` I may also reinforce the endless check strap 20 by means of one or more layers of rubberized fabric 25 wrapped around one half of the unfolded leather strip. or throughout its entire width. The fabric is secured in place by means of cement, and thereafter the strap dures described above. It is also feasible to stitch or sew the two leather pieces together with a fabric layer therebetween and thus hold the'fabric solely by means of the thread stitching.

The operation and use of this check strap will be obvious. Its utility will be apparent from the fact that leather is a material which'stretches readily and to a considerable extent. But the reinforcementof fabric or cord is a material of very low and uniform stretchability, so that the.

check strap will stand up for a long time under the pounding action of the picker stick as well as the lateral bending of the check strap and without the length increasing materially. Since the outerl faces of the strap are made solely of checkv strap body, the strap will keep its original length while being flexed and pounded by the friction fingers and picker stick. Also, it will be more uniform in its action and showl greater tensile strength.

Various types of cord material may be used for the purpose, provided it has such resiliency or elasticity. and not brittleness, that it will withstand the shocks and impacts of the pounding picker stick. For example, a resilient twisted steel cord or cable may be wrapped around the inner leather layer according to the method of Figs. 3 and 4. Also, the textile woven fabrics may be made of any suitable material that is shock resistant and has the desired strength; hence the word "textile is to be given a broad interpretation. The term cord applies either to separate non-woven cords or to the strands of a fabric which extend longitudinally of the strap. It will also be understood that this invention applies to the many shapes and arrangements of check straps that may be used, such as a truncated conical shape, as well as the cylindrical form illustrated in the drawings. Hence the above disclosure is to be interpreted as setting forth the principles of my invention and the preferred embodiments and not as imposing limitations on the appended claims.

I claim:

1. A loom check strap for restraining the movement of a picker stick therebetween comprising two outer elongated, friction resistant layers of leather and an intermediate reinforcement of substantial thickness therebetween having cords extending throughout the effective length of the strap and bonding means for securing the cords in position whereby they resist longitudinal stretching of the strap during use and impart stiffness to the strap.

2. A loom check strap for restraining the movement of av picker stick therebetween comprising two outer elongated facings of leather, at least one layer of reinforcing textile fabric therebetween and ,a cementitious mastic of substantial thickness cementing the fabric layer inposition and securing it to the inner sides of the two leather facings, said leather facings receiving the frictional wear of usage and the longitudinal cords of the fabric and the mastic resisting longitudinal stretching of the strap and imparting stiffness thereto.

3. A loom check strap comprising two elongated, friction resistant outer layers of leather, and an intermediate layer having atleast one REFERENCES CITED The following references are of record in the ille of this patent:

I UNITED STATES PATENTS Number Name Date 163.337 Slemmer May 18. 1875 Howarth July 28, 1942 

